ExtraClassSylalbus2009jan-AD7FO

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Rev 2.02 E4B01 Frequency stability is a characteristic of a good harmonic frequency marker. E4B02 Time base accuracy has the most affect on the accuracy of a frequency counter. E4B03 The advantage of using a bridge circuit to measure impedance is that the measurement is based on obtaining a null in voltage, which can be done very precisely. If the ratio between R3 and R4 is the same as the ratio between R1 and R2 the bridge is balanced and the potential (voltage across points B and D will be) 0 volts. Bridges can be built for AC and RF as well as for DC. E4B04 If a frequency counter has a specified accuracy of +/- 1.0 ppm reads 146,520,000 Hz (146.52 MHz), the most the actual frequency being measured could differ from the reading is 146.52 Hz. 1 ppm is I Hz per MHz, therefore at 146.52 MHz the uncertainty would be 1 Hz x 146.52 or 146.52 Hz E4B05 If a frequency counter with a specified accuracy of +/- 0.1 ppm reads 146,520,000 Hz, the most the actual frequency being measured could differ from the reading is 14.652 Hz. 0.1 ppm is 0.1 Hz per MHz, therefore at 146.52 MHz the uncertainty would be 0.1Hz x 146.52 or 14.652 Hz E4B06 If a frequency counter with a specified accuracy of +/- 10 ppm reads 146,520,000 Hz, the most the actual frequency being measured could differ from the reading is 1.4652 KHz. 10 ppm is I0 Hz per MHz, therefore at 146.52 MHz the uncertainty would be 10 Hz x 146.52 or 1,465.2 Hz E4B07 75 watts of power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power. Power output – power reflected = Delivered power or 100 Watts – 25 Watts + 75 Watts E4B08 It is good practice when using an oscilloscope probe to keep the ground connection of the probe as short as possible. The reason for this is that at RF frequencies the ground connection lead will look like and inductor and cause measurement inaccuracies. Jack Tiley <strong>AD7FO</strong> Page 30 3/15/2009
Rev 2.02 E4B09 High impedance input is a characteristic of a good DC voltmeter. The higher the input impedance of the voltmeter, the less of a load it will place on the circuit being measured. Most of today’s digital voltmeters have fixed 10 megohm input impedance. E4B10 If the current reading on an RF ammeter placed in series with the antenna feedline of a transmitter increases as the transmitter is tuned to resonance there will be more power going into the antenna. E4B11 A method used to measure intermodulation distortion in an SSB transmitter is to modulate the transmitter with two non-harmonically related audio frequencies (in the audio pass band of the transmitter) while observing the RF output on a spectrum analyzer. E4B12 When using a portable SWR analyzer to measure antenna resonance and feed-point impedance, connect the antenna feed line directly to the analyzer's test connector. E4B13 Voltmeter sensitivity, expressed in ohms per volt, can be used to determine the input impedance of the voltmeter by taking the full scale reading of the voltmeter multiplied by its ohms per volt rating. This will provide the input impedance (circuit loading resistance) of the voltmeter Example: A 100 volt full scale voltmeter with an input sensitivity of 20,000 ohms per volt would be: 100 x 20,000 or 2,000,000 ohms or 2 megohms E4B14 The compensation of an oscilloscope probe is typically adjusted using a square wave that is observed and the probe is adjusted until the horizontal portions of the displayed wave is as nearly flat as possible E4B15 A less accurate reading will result if a dip-meter is too tightly coupled to a tuned circuit being checked. E4B16 The Coil impedance of a D'Arsonval-type meter limits its accuracy. E4B17 The bandwidth of the circuit's frequency response can be used as a relative measurement of the Q for a seriestuned circuit. The Narrower the bandwidth the higher the Q of the circuit E4C Receiver performance characteristics, part 1: phase noise, capture effect, noise floor, image rejection, MDS, signal-to-noise-ratio; selectivity E4C01 The effect of excessive phase noise in the local oscillator section of a receiver can cause strong signals on nearby frequencies to interfere with reception of weak signals. Jack Tiley <strong>AD7FO</strong> Page 31 3/15/2009
Page 1 and 2: Rev 2.02 Preparing for the Extra cl
Page 3 and 4: Rev 2.02 Guide to using this syllab
Page 5 and 6: Rev 2.02 SUBELEMENT E4 -- AMATEUR R
Page 7 and 8: Rev 2.02 ELEMENT 4 - EXTRA CLASS QU
Page 9 and 10: Rev 2.02 E1A09 (Band Plan Chart) Th
Page 11 and 12: Rev 2.02 E1B13 (FCC Rules) Communic
Page 13 and 14: Rev 2.02 E1D08 (FCC Rules) The 2 me
Page 15 and 16: Rev 2.02 E1E20 (FCC Rules) You must
Page 17 and 18: Rev 2.02 SUBELEMENT E2 - OPERATING
Page 19 and 20: Rev 2.02 E2A13 Geosynchronous satel
Page 21 and 22: Rev 2.02 E2B17 Immunity from fading
Page 23 and 24: Rev 2.02 E2D02 The definition of
Page 25 and 26: Rev 2.02 SUBELEMENT E3 -- RADIO WAV
Page 27 and 28: Rev 2.02 E3C01 Auroral activity cau
Page 29: Rev 2.02 E4A06 A spectrum analyzer
Page 33 and 34: Rev 2.02 E4C06 If t he thermal nois
Page 35 and 36: Rev 2.02 E4D11 Third-order intermod
Page 37 and 38: Rev 2.02 SUBELEMENT E5 -- ELECTRICA
Page 39 and 40: Rev 2.02 E5B Time constants and pha
Page 41 and 42: Rev 2.02 Example 2: To find the ang
Page 43 and 44: Rev 2.02 j 50 -j 25 E5B12 The phase
Page 45 and 46: Rev 2.02 j 600 -j300 E5C04 In polar
Page 47 and 48: Rev 2.02 Parallel circuit solutions
Page 49 and 50: Rev 2.02 R=300 Ω XL= (2 π FL) or
Page 51 and 52: Rev 2.02 Power Factor represents th
Page 53 and 54: Rev 2.02 SUBELEMENT E6 -- CIRCUIT C
Page 55 and 56: Rev 2.02 Field-effect transistors e
Page 57 and 58: Rev 2.02 E6B12 Junction diodes are
Page 59 and 60: Rev 2.02 E6D02 Cathode ray tube (CR
Page 61 and 62: Rev 2.02 E6E04 The technique used t
Page 63 and 64: Rev 2.02 E6F07 Cadmium sulfide will
Page 65 and 66: Rev 2.02 E7A07 An AND gate produces
Page 67 and 68: Rev 2.02 When a Class C rather than
Page 69 and 70: Rev 2.02 E7C01 In a low-pass filter
Page 71 and 72: Rev 2.02 E7D02 One characteristic o
Page 73 and 74: Rev 2.02 E7E05 A pre-emphasis netwo
Page 75 and 76: Rev 2.02 E7F08 One purpose of a mar
Page 77 and 78: Rev 2.02 E7G17 The typical output i
Page 79 and 80: Rev 2.02 E7H19 A phase-locked loop
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Rev 2.02 E8A06 The approximate rati
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Rev 2.02 E8B13 In time division mul
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Rev 2.02 E8D07 An electromagnetic w
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Rev 2.02 E9A10 Antenna bandwidth is
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Rev 2.02 E9B10 The “Method of Mom
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Rev 2.02 E9C09 The elevation angle
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Rev 2.02 E9D09 An advantage of usin
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Rev 2.02 E9E08 An SWR greater than
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Rev 2.02 E9F11 A 1/8-wavelength tra
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Rev 2.02 E9H05 The main drawback of
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Rev 2.02 SUBELEMENT E0 -- SAFETY [1
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Rev 2.02 Jack Tiley AD7FO Page 103
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Rev 2.02 Capacitors in series C= __
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Rev 2.02 Impedance of complex serie
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Rev 2.02 Calculating Component valu
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Rev 2.02 AC Voltage Calculations Th
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Rev 2.02 Jack Tiley AD7FO Page 113
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